/**
 * cli:sources-ingest — validate.ts
 *
 * Spec validation + prerequisites. Doctrine: an error here names its
 * remediation; mode/kind/origin incoherences are refused BEFORE any IO so an
 * empty registry can never mean « inputs were absent ».
 */
import { existsSync } from 'node:fs'
import { isAbsolute, join } from 'node:path'
import { IngestInputSchema, type ValidationResult } from './types.js'

export function validateSpec(raw: unknown, workdir?: string): ValidationResult {
  const parsed = IngestInputSchema.safeParse(raw)
  if (!parsed.success) {
    return {
      valid: false,
      errors: parsed.error.issues.map((i) => `[${i.path.join('.')}] ${i.message}`),
    }
  }
  const spec = parsed.data
  const base = workdir ?? process.cwd()
  const resolvedBaRoot = isAbsolute(spec.baRoot) ? spec.baRoot : join(base, spec.baRoot)
  const errors: string[] = []

  const originIsPath = 'path' in spec.origin
  if (spec.kind === 'file' && !originIsPath) {
    errors.push('kind=file requires origin.path (origin.url is for kind=web).')
  }
  if (spec.kind === 'web' && originIsPath) {
    errors.push('kind=web requires origin.url + origin.fetchedAt (origin.path is for kind=file).')
  }

  let resolvedOriginPath: string | undefined
  if (spec.kind === 'file' && originIsPath) {
    const p = (spec.origin as { path: string }).path
    resolvedOriginPath = isAbsolute(p) ? p : join(base, p)
    if (!existsSync(resolvedOriginPath)) {
      errors.push(`origin.path not found: ${resolvedOriginPath}`)
    }
  }

  if (spec.mode === 'write' && !spec.analysis) {
    errors.push('mode=write requires `analysis` — run mode=plan first, read the content, judge, then write.')
  }
  if (spec.mode === 'register-blocked') {
    if (!spec.reason) {
      errors.push('mode=register-blocked requires `reason` — a typed unread status is an ADMISSION, it says why.')
    }
    if (spec.analysis) {
      errors.push('mode=register-blocked takes no `analysis` — the content is precisely what could not be read.')
    }
  }
  if (spec.supersedes) {
    if (spec.mode !== 'write') {
      errors.push('`supersedes` only makes sense in mode=write — the replacement must actually be ingested.')
    }
    if (spec.as && spec.as === spec.supersedes) {
      errors.push('`as` and `supersedes` on the same code are contradictory — attach OR replace, not both.')
    }
  }
  if (spec.kind === 'web' && spec.copyRaw === true) {
    errors.push('kind=web has no raw/ copy — the citation is URL + fetch date + verbatim extracts.')
  }

  return { valid: errors.length === 0, errors, spec, resolvedBaRoot, resolvedOriginPath }
}